How it began
From the early 1980s Petróleos de Venezuela worked on a technique for dispersing natural bitumen in water in order to commercialize the reserves of the Orinoco belt. The fuel was developed for industrial use by Intevep, the company's research and development affiliate, following earlier collaboration on oil emulsions with BP. An industry account describes a 20-year history that ran from basic and applied research through scale-up to commercial use.
Before it existed
Raw Orinoco bitumen has an extremely high viscosity and a gravity of 8 to 10 degrees API at ambient temperature, which made it unsuitable for direct use in conventional power stations and hard to move to the coast for export. The Orinoco belt, an area of about 20,000 square miles, held an estimated 270 billion barrels of economically recoverable reserves that could not easily be sold.
How it works
Orimulsion is a mixture of about 70 percent bitumen and 30 percent fresh water with a small amount of surfactant that keeps the bitumen droplets suspended. The emulsion can be handled at room temperature with standard equipment, and the water improves the combustion of the bitumen. It can be burned in power stations designed for coal or heavy fuel oil with suitable modification. A magnesium additive was originally included to limit corrosion from vanadium.
How it spread
Orimulsion was used as a fuel for cement and power plants from 1991, and by 2001 more than 30 million tonnes had been burned in commercial installations in several countries. It was carried by pipeline from Morichal to an export terminal at Jose. Customers included power plants in Japan, Italy and China. A reformulated version, Orimulsion 400, replaced the original surfactant and dropped the magnesium additive.
Who pushed back
European rules restricted the nonylphenol ethoxylate surfactant used in the first formula because of its effect on aquatic systems, and customers reported fouling of boiler tubes from the magnesium additive. Spills were a concern because the emulsion breaks down in water and the bitumen separates. After the 2002-03 general strike in Venezuela the government moved to phase out the program, and production was reported to have ceased in 2006.
